Variable current sinking for coarse/fine programming of non-volatile memory
AssigneeSanDisk Corporation
InventorsDaniel Guterman, Nima Mokhlesi, Yupin Fong
Life of this patent
Estimating the term…
Abstract
A non-volatile memory device is programmed by first performing a coarse programming process and subsequently performing a fine programming process. The coarse/fine programming methodology is enhanced by using an efficient verification scheme that allows some non-volatile memory cells to be verified for the coarse programming process while other non-volatile memory cells are verified for the fine programming process. The fine programming process can be accomplished using current sinking, charge packet metering or other suitable means.
Claims31
An apparatus for programming, comprising:
- a non-volatile storage element having a gate and two control terminals;
- and
- a switchable current sinking device in communication with one of said control terminals, said switchable current sinking device being switchable between a coarse mode and a fine mode in response to a determination that said non-volatile storage element is in a coarse programming mode or a fine programming mode, respectively, said switchable current sinking device provides a coarse current sink to said one of said control terminals when in the coarse mode, and a fine current sink to said one of said control terminals when in the fine mode.
An apparatus for programming non-volatile storage elements, comprising:
- one or more switchable current sink circuits in communication with said non-volatile storage elements, said one or more switchable current sink circuits cause a first subset of said non-volatile storage elements which are in a coarse programming phase to be subjected to a first current sink while, concurrently, a second subset of said non-volatile storage elements which are in a fine programming phase are subjected to a second current sink.
An apparatus for programming, comprising:
- means for performing coarse and fine programming for non-volatile storage elements;
- means, associated with said means for performing, for sinking first and second currents during said coarse and fine programming, respectively;
- means for switchably controlling said means for sinking so that said means for sinking sinks said first current during said coarse programming, and said second current during said fine programming, said means for switchably controlling is responsive to a determination that said non-volatile storage elements are in a coarse or fine programming mode.
A method for programming, comprising:
- performing a coarse programming phase for a non-volatile storage element by sinking a first current responsive to a determination that said non-volatile storage element is in a coarse programming mode;
- and
- performing a fine programming phase for said non-volatile storage element by sinking a second current responsive to a determination that said non-volatile storage element is in a fine programming mode.
Dependencies are inferred from the claim text.